Fume hoods for removing fumes, vapors, potentially harmful gases, and particulates, etc., from laboratories, work areas and instructional type settings are fairly well known. Currently, most fume hoods comprise large, cabinet-type structures that are typically anchored in place. An example of an anchored type fume hood is generally disclosed in U.S. Pat. No. 6,080,058. Anchored type fume hoods generally comprise a plurality of flat, rectangular walls that form rectangular parallelepipeds. The front walls of these types of fume hood typically comprise a planar sash that may be raised and lowered to allow access to a work area. Typically, an area of low pressure is created within the cabinet structure by means of a fixed ventilation system, which draws air into the fume hood and evacuates any contaminated air out of the work area.
A problem with anchored fume hoods is that they are large, noisy, non-movable, obstructive and expensive. Because of their large size, anchored fume hoods are usually fixed in place and/or are placed in out of the way locations within a laboratories or classrooms. This can be problematic when laboratory or classroom instruction is required. For example, it can be difficult to assemble several individuals around an anchored fume hood in order to provide proper instruction. Also, the large size of the anchored fume hoods can block individuals' fields of vision/lines of sight during regular classroom instruction. Moreover, because they typically comprise small ventilation openings, anchored fume hoods usually require high fume hood velocities to effectively remove air from the work area; the high fume velocities typically create excessive noise. Additionally, because of their size and expense, only a limited number of anchored fume hoods may be affordable or be capable of being conveniently placed within a typical laboratory or classroom setting. As a result, the size and expense of anchored fume hoods can have the effect of limiting the number of individuals that may be safely present within a laboratory or classroom. While argument exists that it may be desirous to limit laboratory or class size and utilize large anchored fume hoods when extremely dangerous substances are used, in many instances, anchored fume hoods simply are not required. As a result, more compact, desktop-type fume hoods have been developed.
Current desktop-type fume hoods generally resemble anchored fume hoods in that they typically comprise a plurality of rectangular walls that form rectangular parallelepipeds; however, such devices are generally smaller and able of being placed on laboratory benches or desktops. The front walls of such compact desktop-type fume hoods typically comprise planar sashes that may be raised and lowered to allow access to a work area under the hood. The rectangular footprint of these fume hoods can make it difficult, from ergonomic standpoints, for individuals to work under the fume hood and/or they tend to limit and obstruct the work area. Additionally, the rectangular configuration of the fume hood tends to produce inefficient air flow into and out of the fume hood. Moreover, in many instances, such fume hoods are formed from plastics or other materials that may be highly reactive with several chemicals commonly used in laboratories and/or are prone to catching fire. Additionally, such compact, desktop-type fume hoods require separate ventilation ducts, or filtering devices, for each fume hood. Finally, known compact, desktop-type fume hoods cannot be broken down into smaller components after use for more convenient storage.
What is needed then is a compact and portable desktop-type ventilation system which overcomes these, and other, disadvantages.